The invention relates to the technical field of shell fabric weaving and specifically relates to a double-layer air layer pure separation shell fabric capable of being tailored at will. The double-layer air layer pure separation shell fabric an upper-layer plain single face and a lower-layer plain single face, wherein the upper-layer plain single face and the lower-layer plain single face are woven from 20 D asahi kasei spandex and 40 S/1 toyobo acrylic fiber yarns, the upper-layer plain single face and the lower-layer plain single face are woven and connected together through spandex betweenthe upper-layer plain single face and the lower-layer plain single face, an a thermal-insulation air layer is formed between the upper-layer plain single face and the lower-layer plain single face, the spandex is chosen from asahi kasei 30 D spandex, and the double-layer air layer pure separation shell fabric capable of being tailored at will is woven by a six-way circular weaving method. The double-layer air layer pure separation shell fabric disclosed by the invention has the advantages that upper-layer gray cloth and lower-layer gray cloth are connected through the spandex, no chemical adhesion aid is utilized, and environmental friendliness and hygiene are achieved; the double-layer air layer pure separation shell fabric disclosed by the invention is of a unique lock structure, so thatthe shell fabric can be tailored at will, and the problem of hemming of the shell fabric after being tailored is solved; the thermal-insulation air layer is formed between the two layers of cloth, sothat the fabric has more thermal insulation and good breathability.